Introduction

In Unit 2, you learned about factors that limit a population's ability to grow. One of the major factors that limits an ecosystem's carrying capacity and controls a population's ability to grow is the amount of available water.

Just like food, water is essential for life to exist on Earth. All organisms rely on water to help carry out physiological processes life processes . In some organisms, water makes up 90% of their body. The human body consists up to 60% water. In newborns, it is about 78%.

Water serves many essential functions in humans, such as

  • building material for cells;
  • regulating internal body temperature;
  • transporting nutrients;
  • assisting in flushing waste from the body;
  • acting as a shock absorber for the brain, spinal cord, and fetuses
  • forming saliva which helps with digestion;
  • lubricating joints.

Read The water in you from the USGS Water Science School for more information.

Under normal conditions, the average human can only go about 3-4 days without water compared to several weeks without food.

Without water, life on Earth would not exist. It is important that organisms have access to pollution-free freshwater. In this lesson, you will explore the properties of water and how these properties make water essential for all life.

Lesson Objectives

Following successful completion of this lesson, students will be able to...

  • Identify the properties of water.
  • Explain why water is considered the universal solvent.
  • Explain and give examples of why the properties of water make it essential to life.

Enduring Understanding:

  • Without water and its unique properties, life on Earth would not exist.

The above objectives correspond with the Alabama Course of Study: Environmental Science Objective: 10

This lesson incorporates the following Literacy Standards: R1, R2, R3, R4, R5, R6, R7, R10, W1, W2, W3, W4, W8, W9, and W10

 

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